Unity3d 在移动设备上的摇杆控制 C#

using UnityEngine;  
    [RequireComponent(typeof(GUITexture))] 
    public class MPJoystick : MonoBehaviour 
    { 
     
           class Boundary
           { 
                 public Vector2 min = Vector2.zero; 
                 public Vector2 max = Vector2.zero; 
           } 
    private static MPJoystick[] joysticks;   // A static collection of all joysticks 
     
    private static bool enumeratedJoysticks = false; 
     
    private static float tapTimeDelta = 0.3f;    // Time allowed between taps 
    public bool touchPad; 
     
    public Vector2 position = Vector2.zero; 
     
    public Rect touchZone; 
     
    public Vector2 deadZone = Vector2.zero;  // Control when position is output 
     
    public bool normalize = false; // Normalize output after the dead-zone? 
     
    public int tapCount;      
     
    private int lastFingerId = -1;   // Finger last used for this joystick 
     
    private float tapTimeWindow;     // How much time there is left for a tap to occur 
     
    private Vector2 fingerDownPos; 
     
    private GUITexture gui; 
     
    private Rect defaultRect;    // Default position / extents of the joystick graphic 
     
    private Boundary guiBoundary = new Boundary();   // Boundary for joystick graphic 
     
    private Vector2 guiTouchOffset;  // Offset to apply to touch input 
     
    private Vector2 guiCenter;   // Center of joystick 
    void Start() { 
     
    gui = (GUITexture)GetComponent(typeof(GUITexture)); 
    defaultRect = gui.pixelInset; 
     
    defaultRect.x += transform.position.x * Screen.width;// + gui.pixelInset.x; // -  Screen.width * 0.5; 
     
    defaultRect.y += transform.position.y * Screen.height;// - Screen.height * 0.5; 
    transform.position = Vector3.zero; 
    if (touchPad) { 
     
    // If a texture has been assigned, then use the rect ferom the gui as our touchZone 
     
    if ( gui.texture ) 
     
    touchZone = defaultRect; 
     
    } else { 
     
    guiTouchOffset.x = defaultRect.width * 0.5f; 
     
    guiTouchOffset.y = defaultRect.height * 0.5f; 
    // Cache the center of the GUI, since it doesn't change 
     
    guiCenter.x = defaultRect.x + guiTouchOffset.x; 
     
    guiCenter.y = defaultRect.y + guiTouchOffset.y; 
    // Let's build the GUI boundary, so we can clamp joystick movement 
     
    guiBoundary.min.x = defaultRect.x - guiTouchOffset.x; 
     
    guiBoundary.max.x = defaultRect.x + guiTouchOffset.x; 
     
    guiBoundary.min.y = defaultRect.y - guiTouchOffset.y; 
     
    guiBoundary.max.y = defaultRect.y + guiTouchOffset.y; 
     
    } 
     
    } 
    public Vector2 getGUICenter() { 
     
    return guiCenter; 
     
    } 
    void Disable() { 
     
    gameObject.active = false; 
          
    } 
    private void ResetJoystick() { 
     
    gui.pixelInset = defaultRect; 
     
    lastFingerId = -1; 
     
    position = Vector2.zero; 
     
    fingerDownPos = Vector2.zero; 
     
    } 
    private bool IsFingerDown() { 
     
    return (lastFingerId != -1); 
     
    } 
    public void LatchedFinger(int fingerId) { 
     
    // If another joystick has latched this finger, then we must release it 
     
    if ( lastFingerId == fingerId ) 
     
    ResetJoystick(); 
     
    } 
    void Update() { 
     
    if (!enumeratedJoysticks) { 
     
    // Collect all joysticks in the game, so we can relay finger latching messages 
     
    joysticks = (MPJoystick[])FindObjectsOfType(typeof(MPJoystick)); 
     
    enumeratedJoysticks = true; 
     
    } 
    int count = Input.touchCount; 
    if ( tapTimeWindow > 0 ) 
    tapTimeWindow -= Time.deltaTime; 
    else
    tapCount = 0; 
    if ( count == 0 ) 
    ResetJoystick(); 
    else
    { 
         for(int i = 0; i < count; i++)
         { 
              Touch touch = Input.GetTouch(i); 
               Vector2 guiTouchPos = touch.position - guiTouchOffset; 
               bool shouldLatchFinger = false; 
               if (touchPad)
              { 
                     if (touchZone.Contains(touch.position)) 
                         shouldLatchFinger = true; 
              } 
              else if (gui.HitTest(touch.position)) 
              { shouldLatchFinger = true;} 
    // Latch the finger if this is a new touch 
     
    if (shouldLatchFinger && (lastFingerId == -1 || lastFingerId != touch.fingerId ))
    { 
    if (touchPad) {lastFingerId = touch.fingerId; } 
    lastFingerId = touch.fingerId; 
    // Accumulate taps if it is within the time window 
    if ( tapTimeWindow > 0 ) 
       tapCount++; 
    else { 
     
    tapCount = 1; 
     
    tapTimeWindow = tapTimeDelta; 
     
    } 
    // Tell other joysticks we've latched this finger 
          
    foreach (MPJoystick j in joysticks) 
    { 
     
    if (j != this)  
     
    j.LatchedFinger( touch.fingerId ); 
     
    } 
     
    }    
    if ( lastFingerId == touch.fingerId ) { 
     
    // Override the tap count with what the iPhone SDK reports if it is greater 
     
    // This is a workaround, since the iPhone SDK does not currently track taps 
     
    // for multiple touches 
     
    if ( touch.tapCount > tapCount ) 
     
    tapCount = touch.tapCount; 
    if ( touchPad ) { 
     
    // For a touchpad, let's just set the position directly based on distance from initial touchdown 
     
    position.x = Mathf.Clamp( ( touch.position.x - fingerDownPos.x ) / ( touchZone.width / 2 ), -1, 1 ); 
     
    position.y = Mathf.Clamp( ( touch.position.y - fingerDownPos.y ) / ( touchZone.height / 2 ), -1, 1 ); 
     
    } else { 
     
    // Change the location of the joystick graphic to match where the touch is 
     
    Rect r = gui.pixelInset; 
     
    r.x =  Mathf.Clamp( guiTouchPos.x, guiBoundary.min.x, guiBoundary.max.x ); 
     
    r.y =  Mathf.Clamp( guiTouchPos.y, guiBoundary.min.y, guiBoundary.max.y ); 
     
    gui.pixelInset = r; 
     
    } 
    if (touch.phase == TouchPhase.Ended || touch.phase == TouchPhase.Canceled) 
     
    ResetJoystick(); 
     
    } 
     
    } 
     
    } 
    if (!touchPad) { 
     
    // Get a value between -1 and 1 based on the joystick graphic location 
     
    position.x = ( gui.pixelInset.x + guiTouchOffset.x - guiCenter.x ) / guiTouchOffset.x; 
     
    position.y = ( gui.pixelInset.y + guiTouchOffset.y - guiCenter.y ) / guiTouchOffset.y; 
     
    } 
    // Adjust for dead zone 
     
    var absoluteX = Mathf.Abs( position.x ); 
     
    var absoluteY = Mathf.Abs( position.y ); 
     
      
     
    if (absoluteX < deadZone.x) { 
     
    // Report the joystick as being at the center if it is within the dead zone 
     
    position.x = 0; 
     
    } 
     
    else if (normalize) { 
     
    // Rescale the output after taking the dead zone into account 
     
    position.x = Mathf.Sign( position.x ) * ( absoluteX - deadZone.x ) / ( 1 - deadZone.x ); 
     
    } 
    if (absoluteY < deadZone.y) { 
     
    // Report the joystick as being at the center if it is within the dead zone 
     
    position.y = 0; 
     
    } 
     
    else if (normalize) { 
     
    // Rescale the output after taking the dead zone into account 
     
    position.y = Mathf.Sign( position.y ) * ( absoluteY - deadZone.y ) / ( 1 - deadZone.y ); 
     
    } 
    } 
    }